U.S. Park Police on horseback and on foot with riot gear swept into McPherson Square just after 5:30 a.m. As a helicopter circled overhead and horses’ hooves clattered on the pavement, protesters ran through the camp trying to wake up those still sleeping.

Streets within two blocks of the downtown park were shut down because of the raid, which was characterized as “further enforcement” of a no-camping crackdown that began Monday.

In the square, where protesters once slept, ate hot meals and snuggled in friendly “cuddle puddles,” they can now stay overnight only if they stay awake, keeping only unfurnished tents for the purpose of a round-the-clock vigil, police said.

“They can have the tents for symbolic purposes only. So long as there is compliance, we will have no issues,” said Sgt. David Schlosser, a Park Police spokesman. “Their First Amendment rights are paramount.”

Protesters and police at first interacted in good humor Saturday as they negotiated taking down the big blue “Tent of Dreams,” which protesters had unfurled over a Civil War statue Monday. But relations grew tense as the day wore on and police began clearing the park of several truckloads of bedding and trash. At one point, dozens of officers pushed back the crowd with riot shields so they could erect more barricades.

“We’re being evicted without tear gas,” said Melissa Byrne, a protester from the District of Columbia.

Schlosser said that police had moved in to do temporary “nuisance abatement” and that cleaning crews had found health hazards that included filthy bedding, bottles full of urine and several dead rats.